A new study has dealt a blow to the reputation of bonobos as and the most loving and caring of primates. Researchers following the apes through the forests of the Democratic Republic of Congo observed 5 instances when the bonobos hunted monkeys, including three successful hunts where the apes began devouring their prey even before it was dead. Says lead researcher Gottfried Hohmann: “Bonobos are merciless…. [T]hey catch it and start eating it. They don’t bother to kill it” [New Scientist].

While bonobos primarily eat fruit, researchers have known for some time that the apes supplement their diet with rodents and small antelopes. This study is the first to include other primates in their food supply, a finding that shows them to be surprisingly similar to chimpanzees, who sometimes hunt monkeys. Bonobos are generally considered more peaceful than their close cousins, the chimps, and have a reputation for free-loving ways because sex plays a major role their society, being used for greetings, conflict resolution and reconciliation [Reuters].

Hohmann’s report, published in Current Biology [subscription required], calls into question the earlier theory that the bonobos’ matriarchal society makes them both more peaceable and less inclined to hunt. Says Hohmann: “In chimpanzees, male-dominance is associated with physical violence, hunting and meat consumption. By inference, the lack of male dominance and physical violence is often used to explain the relative absence of hunting and meat-eating in bonobos. Our observations suggest that, in contrast to previous assumptions, these behaviors may persist in societies with different social relations” [LiveScience].

Bonobos expert Frans de Waal agrees that the hunting behavior adds a new dimension to what’s known of bonobos’ habits and lifestyle, but he notes that predation and aggression are distinct behaviours, pointing out aggressive herbivores such as bison and sociable carnivores such as lionesses as examples. “For me, this finding does very little to change the idea of bonobos as relatively peaceful primates” [New Scientist].